1. Field of Invention
The present invention relates to auto exposure. More particularly, the present invention relates to a method to control auto exposure with an image extraction apparatus.
2. Description of Related Art
Since virtual environments are complex, pictures of objects and backlight that are varied with time, using a digital camera with a flashlight to take the pictures are generally underexposed or overexposed. Thus, in such conditions the pictures are not satisfactory. To overcome this problem conventionally, a reference sample image is taken before the flashlight is turned on. Then, different companies have respectively different designs to calculate and configure parameters to shine the flashlight based on the reference sample image, the parameters such as flashing time period and light brightness. Thus, the flashlight is turned on and shines brightly for illumination based on the calculated flashing parameters. However, the aforementioned method cannot handle or control the resultant exposure of the object after the flashlight is activated. Therefore, underexposing or overexposing problems may still occur in some circumstances.
Therefore, there is a need to provide an improved image extraction apparatus and a method to control auto exposure to mitigate or obviate the aforementioned problems.